With reference to FIG. 6 for a conventional ceiling fan motor, the conventional ceiling fan motor 40 comprises an upper casing 41, a middle ring 42, a lower casing 43 and a stator 44, and the upper casing 41 and the lower casing 43 are engaged with upper and lower sides of the middle ring 42 respectively, and a plurality of screws 45 are passed and combined between the upper casing 41 and the lower casing 43, and after the upper casing 41, the middle ring 42 and the lower casing 43 are combined, an accommodating space is formed for accommodating a stator 44, and a rotor 420 is installed around an inner sidewall of the middle ring 42. The aforementioned structure constitutes a ceiling fan motor 40. Another conventional ceiling fan motor may comprise the upper casing 41, the lower casing 43 and the stator 44 only. However, the overall structure includes many components and thus causes an inconvenient assembling process, and a flange is extended outwardly from edges of the upper and lower casings 41, 43 for passing and combining the screws 45, so that it is necessary to increase the width of the ceiling fan motor 40. In addition, there is a wire winding space difference of the stator 44 inside the ceiling fan motor 40.